Sciropescire Caustow Castle Hoard Map
The map shows a drawing of a castle with an X marks the spot in a lake.
Map pickup location:
Hill Gate Remnants - Sciropescire
Inside the ruined tower, there is a weak wall at ground floor you can break.
Shoot down the big hanging bag, climb down, slide through the gap and pick up the map.
Castow Castle - Sciropescire
The Treasure loot is in the lake north of Castow Castle.
Get into the lake right where the pier ends and you'll get the loot prompt.